TF-3696 Upgrade XCODE version to 16.0 on CI

Signed-off-by: dab246 <[email protected]>

Author: dab246

.github/workflows/build.yaml

@@ -7,7 +7,7 @@ name: Build dev binaries
 
 env:
   FLUTTER_VERSION: 3.24.5
-  XCODE_VERSION: ^15.0.1
+  XCODE_VERSION: 16.0
 
 jobs:
   build-app:
@@ -19,7 +19,7 @@ jobs:
           - os: android
             runner: ubuntu-latest
           - os: ios
-            runner: macos-latest
+            runner: macos-14 # Use macos-14 runners because Xcode 16 only exists on macOS 14+.
     environment: dev
 
     steps:

.github/workflows/release.yaml

@@ -7,7 +7,7 @@ name: Release
 
 env:
   FLUTTER_VERSION: 3.24.5
-  XCODE_VERSION: ^15.0.1
+  XCODE_VERSION: 16.0
 
 jobs:
   release:
@@ -20,7 +20,7 @@ jobs:
           - os: android
             runner: ubuntu-latest
           - os: ios
-            runner: macos-latest
+            runner: macos-14 # Use macos-14 runners because Xcode 16 only exists on macOS 14+.
       fail-fast: false
 
     environment: prod